JPH08230373A - Ball point pen - Google Patents

Abstract

PURPOSE: To provide a simple structure which is easily manufactured in a ball point pen equipped with a back flow check mechanism by a method wherein a control wall part in contact with a valve plug has a smooth ink distributing function and a sufficient contact function. CONSTITUTION: A valve chamber 6 is provided to an ink distributing passage 5 between a pen point 3 and an ink storing part 4. A globular valve plug 9 for prevention of back flow is lengthwise freely movably housed in the valve chamber 6. A control wall part 7 to which the valve plug 9 when transferred forward can stick fast, is provided in front of the valve chamber 6. Besides, a valve seat 8 to which the valve plug 9 when transferred backward can stick fast, is provided on a rear side of the valve chamber 6. Then, an inclined plane part 71 inclined to a shaft center is provided to the control wall part 7.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a ballpoint pen.
More specifically, the present invention relates to a ballpoint pen in which a valve chamber that accommodates a backflow prevention valve element in a back-and-forth movable manner is provided in an ink flow passage between a pen tip and an ink storage portion.

[0002]

2. Description of the Related Art Conventionally, a ballpoint pen having an ink backflow prevention mechanism is disclosed in Japanese Utility Model Publication No. 54-15703.
A configuration is disclosed in which ink grooves are radially formed on the rear end surface of the chip body and the valve balls are received by the rear end surface. However, since the conventional structure has a structure in which the ink groove is formed on the regulation wall portion with which the ball abuts, that is, the rear end surface of the chip body, it requires a precise processing step and is difficult to manufacture.

Japanese Utility Model Publication No. 4-52067 discloses that
For the purpose of reducing the complexity of processing the ink groove, a configuration is disclosed in which a required number of protrusions are integrally formed on the inner surface of the valve chamber with a synthetic resin, and the protrusions make it impossible to eject the balls. However, the above-mentioned conventional structure has a structure in which the ball is press-fitted into the valve chamber while elastically deforming the ridge from the direction of the ridge, and the ridge is an undercut when molding. The ridge is not very large,
It is set relatively small. Specifically, the diameter of the virtual inscribed circle of the ridge is set to be slightly smaller than the outer diameter of the ball. As a result, the ink flow gap formed when the ridge and the ball are brought into contact with each other is not sufficiently secured, which may impede smooth ink flow during writing.
Furthermore, when the process has a step of pushing out the ink to the pen tip side by the centrifuge, there is a possibility that the ball may be eaten by the ridge.

[0004]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems, and has a regulating wall portion having a smooth ink circulation function at the time of writing and a sufficient contact function without biting with the valve body. An object of the present invention is to provide a ballpoint pen having a check valve mechanism, which has a simple structure and is easy to manufacture.

[0005]

SUMMARY OF THE INVENTION In the present invention, an ink flow passage between a pen tip 3 and an ink containing portion 4 is provided in a valve chamber 6 in which a backflow preventing valve 9 is housed so as to be movable back and forth. Provided in 5,
Further, a regulation wall portion 7 is provided on the front side of the valve chamber 6 (the pen tip 3 side) with which the valve body 9 can come into contact when moved forward, while the rear side of the valve chamber 6 (the ink containing portion). (4 side) is a ballpoint pen provided with a valve seat 8 to which a valve body 9 can be brought into close contact when moved rearward, wherein the regulating wall portion 7 is provided with an inclined flat surface portion 71 inclined with respect to the axis. Is a requirement.

Further, in the above structure, the through hole 51 for communicating the pen tip 3 side and the inside of the valve chamber 6 is formed with the inclined flat surface portion 71.
It is preferable that the opening connection is made.

Further, in the above construction, it is effective that the valve body 9 has a spherical shape and that the through hole 51 has a circular cross section. Further, the inclined plane portion 71 may be formed on the entire regulation wall portion 7 (entire surface), or may be formed on the regulation wall portion 7.
May be formed in a part of. Further, the number of the inclined flat surface portions 71 may be one (one surface) or two (two surfaces) or more, but two or less (two surfaces), which is a simple manufacturing process. Is preferred.

In the above structure, the holder 2 made of synthetic resin, which holds the ball-point pen tip 1 in the front part and has the valve chamber 6 inside, is fixed to the opening of the tip end of the ink containing tube 41. It is preferable that either one of the wall portion 7 and the valve seat 8 is provided integrally with the inner wall of the holder 2 and the remaining one is provided separately from the inner wall of the holder 2. (See FIGS. 1, 5, and 7)

Further, a member having the inclined flat surface portion 71 at the rear end portion (for example, the holder 2 for holding the ballpoint pen tip 1 at the front portion, or the ballpoint pen tip 1 for rotatably holding the ball 14 at the tip) is used as a valve. A configuration in which the chamber 6 is press-fitted in the front part is effective. (See FIGS. 3, 5, and 9)

[0010]

By providing the regulating wall portion 7 with the inclined flat surface portion 71 which is inclined with respect to the axis, when the regulating wall portion 7 and the valve body 9 come into contact with each other, the regulating wall portion 7 is provided between the valve body 9 and the through hole 51. A relatively large ink flow gap can be formed in the front-rear direction, and ink can be smoothly supplied to the pen tip 3 during writing.

Further, since the regulating wall portion 7 is provided with the inclined flat surface portion 71, the valve body 9 is moved outward from the axis in the process of treating the ballpoint pen main body with the centrifuge when filling the ballpoint pen ink. The valve body 9 is inserted in the through hole 51 of the shaft center.
Less bite.

Further, the valve chamber 6 is provided in the holder 2, one of the restriction wall portion 7 and the valve seat 8 is provided integrally with the holder 2, and the other one is provided separately from the holder 2. Thus, the valve chamber 6, the restriction wall portion 7, and the valve seat 8 can be easily configured by two members. Further, since the valve body 9 is not configured to press over the inwardly protruding restricting wall portion 7 and the valve seat 8 as in the conventional case, the valve body 9 can be easily inserted into the valve chamber 6 and sufficient contact can be achieved. It is possible to obtain the regulation wall portion 7 having a function and an ink distribution function. Further, the holder 2 after the valve chamber 6 is previously formed inside can be attached to the ink containing tube 41, and the assembling process is easy.

Further, since the rear end portion of the member having the inclined flat surface portion 71 at the rear end is sharpened by the inclined flat surface portion 71, a tapered chamfer or a curved surface is formed on the outer periphery of the rear end edge as in the prior art. It can be easily inserted into the valve chamber 6 without performing the step, and the assembling work becomes smoother.

[0014]

Embodiments of the present invention will be described with reference to the drawings.

A first embodiment is shown in FIGS. 1 and 2. In this embodiment, the ink containing tube 41 and the ball-point pen tip 1 made of metal are used.
Is a refill having a structure in which it is connected via a holder 2 made of a synthetic resin of a tubular connecting member, that is, a replaceable ballpoint pen refill that is housed in a main body (not shown) having a grip portion. In the refill, the ball-point pen tip 1 and the support cylinder 16 are fixed to the tip of the holder 2, and the holder 2 in which the ball-point pen tip 1 (pen tip 3) and the support cylinder 16 are fixed is fixed to the ink storage tube 41. It is a structure that is press-fitted and fixed to the opening at the tip.

The ink containing tube 41 is made of a relatively hard material, that is, synthetic resin (for example, polyacetal, polypropylene, polyethylene, ABS resin, PET resin, etc.).
Or metal (for example, copper alloy such as brass or stainless steel). Thereby, the holder 2 is securely held without wobbling. Incidentally, the ink containing tube 41 of the present embodiment
Is a cylindrical injection-molded body made of transparent or translucent synthetic resin (for example, polypropylene or polyethylene), and has a small diameter portion 41a, a medium diameter portion 41b, and
And a large-diameter portion (not shown) are integrally connected.

In the ink containing portion 4 (medium diameter portion 41b and large diameter portion) of the ink containing pipe 41, a low-viscosity ink, a low-viscosity to medium-viscosity oily ink, or an ink having a shear thinning viscosity (for example, , Ink having a viscosity at a shear rate of 384 s ⁻¹ of 10 to 150 mPa · s at a temperature of 20 ° C. is stored. A backflow preventing agent (for example, a grease-like material) that moves forward as the ink is consumed is stored at the rear end of the ink.

The holder 2 is provided with the ink containing tube 41.
Similar to a relatively hard material, that is, a synthetic resin (for example,
Polyacetal, polypropylene, polyethylene, AB
S resin) or metal (for example, copper alloy such as brass or stainless steel). Thereby, the ball-point pen tip 1 is securely held without wobbling. In this embodiment, a polypropylene resin injection molded body is used.

The holder 2 has a chip mounting hole 2 at the front.
1 and the locking wall portion 22 are provided, and the ballpoint pen tip 1
At the same time, the rear end is brought into contact with the locking wall portion 22, and at the same time, the outer periphery of the rear portion is press-fitted and fixed in the chip mounting hole 21. A through hole 51 (having an inner diameter substantially the same as the inner diameter of the pipe 11 of the ball-point pen tip 1) having a circular cross section is formed through the locking wall portion 22, and the tip mounting hole 21 and a through hole 23 at the rear portion thereof are provided. It communicates with the (ink flow passage 5). A mounting cylinder portion 24 is provided so as to project from the rear portion of the holder 2, and the mounting cylinder portion 24 is press-fitted and fixed to the tip opening portion (the inner peripheral surface of the small diameter portion 41a) of the ink containing pipe 41. A step 25 is formed at the base of the mounting tube 24, and the step 25
The leading edge of the small diameter portion 41a is in contact with.

A valve chamber 6 for accommodating a valve body 9 for preventing backflow so as to be movable back and forth is provided in the circulation hole 23. Specifically, a metallic spherical valve body 9 is inserted into the flow hole 23 from the rear end opening of the holder 2, and then made of metal or synthetic resin (including synthetic rubber and various elastomers). An annular body 81 made of steel is press-fitted from the rear end opening of the holder 2 and fixed to the inner peripheral surface of the flow hole 23. The annular body 81 has a valve hole 81 having an inner diameter smaller than the outer diameter of the valve body 9.
The valve seat 8 is formed by the front end surface of the annular body 81.

Further, the bottom portion of the flow hole 23 is formed into an inclined flat surface, and a regulation wall portion 7 is formed which can come into contact with the valve body 9 when moved forward. The regulation wall portion 7
A through hole 51 is opened in the (slanted plane portion 71), and the through hole 51
The opening edge of has an elliptical shape. As a result, even if the spherical valve element 9 comes into contact with the valve element 9, the valve element 9 allows the through hole 5 to pass through.
1 is not blocked, and a relatively large ink flow gap is formed in the front-rear direction.

The regulation wall portion 7 has a simple structure composed of the inclined flat surface portion 71, and does not have a complicated shape such as a protrusion or a groove as in the conventional case, and therefore is easy to manufacture. Particularly, as described above, when the holder 2 is obtained by injection molding of synthetic resin, it is possible to reduce the manufacturing cost of the mold.

The inclination angle of the inclined plane portion 71 of the regulating portion is 30 ° to 80 °, preferably 40 ° to the axis.
70 degrees is effective. Thereby, the regulation wall portion 7 and the valve chamber 6
There is no fear that the valve body 9 will bite between itself and the inner peripheral surface, and in addition, a large ink flow gap during writing can be sufficiently secured. In addition, the outer diameter of the spherical valve body 9 is equal to that of the valve chamber 6
It is preferable that it is slightly smaller than the inner diameter of the (circulation hole 23) and at the same time larger than 1.5 times (preferably twice) the inner diameter of the through hole 51 to prevent biting.

The ball-point pen tip 1 used in this embodiment is a so-called pipe type ball-point pen, and comprises a metal-made (for example, stainless steel) cylindrical pipe 11 having a substantially uniform wall thickness. In the vicinity of the tip of the pipe 11, a plurality of inward projections formed by radially outwardly pressingly deforming (plastically deforming) a plurality of locations (three or more locations) on the outer circumferential surface at equal intervals are provided. The seat 13 is formed. An inwardly tapered tip edge portion 12 is formed at the tip of the pipe 11 by being pressed and deformed (plastically deformed) inward. A ball 14 made of cemented carbide is arranged between the front surface of the ball receiving seat 13 and the rear surface of the tip edge portion 12, and the ball 14 is rotatable by the ball receiving seat 13 and the tip edge portion 12. Hugged by. Here, the outer diameter of the pipe 11 is 1.1 mm or less, the wall thickness of the pipe 11 is 0.15 mm or less, and the outer diameter of the ball 14 is 0.
It is effective to use a ballpoint pen tip having a width of 75 mm or less, which allows the ballpoint pen tip 1 having a narrow handwriting width to be applied. More preferably, the outer diameter of the pipe 11 is 0.75 mm or less, the wall thickness of the pipe 11 is 0.15 mm or less, and the balls 14 are
An outer diameter of 0.45 mm or less is effective, and as a result, an ultrafine ballpoint pen tip 1 with a narrower handwriting width
Can be applied.

In this embodiment, since the ball-point pen tip 1 is in the shape of a pipe having a small diameter, wobbling and bending tend to occur during writing, but for the purpose of preventing them, the front part of the holder 2 is made of metal. A support tube 16 made of metal is externally fitted and fixed. The support cylinder 16 has a small-diameter front part supporting the outer peripheral surface of the ball-point pen tip 1, and a large-diameter rear part attached to the front peripheral surface of the holder 2.

A second embodiment of the present invention is shown in FIGS. At the tip opening of the ink containing tube 41, a holder 2 having a ball-point pen tip 1 and a support tube 16 having the same structure as in the first embodiment at the front is press-fitted and fixed. The ink containing tube 41 is a straight tubular extruded product of transparent or translucent synthetic resin (for example, polyethylene, polypropylene, etc.), and is cut to an appropriate length. Inside it,
An ink container 4 is provided and is filled with the same ink and backflow preventive as in the first embodiment.

On the inner peripheral surface of the front portion of the ink containing tube 41,
An annular body 81 made of a synthetic resin or a metal, which has a valve hole 81a in the axial center and a conical concave valve seat 8 in a front-rear symmetrical position.
Is press-fitted and fixed. A metallic spherical valve element 9 is accommodated in the ink containing tube 41 (valve chamber 6) between the rear end of the holder 2 and the annular body 81 so as to be movable back and forth.

The holder 2 is a cylindrical connecting member for connecting the pen tip 3 and the ink containing tube 41, and is made of the same synthetic resin (for example, polyacetal, polypropylene, polyethylene, ABS resin) or metal as in the first embodiment. (For example, a copper alloy such as brass or stainless steel). Further, the holder 2 has a chip mounting hole 21 and a through hole 51 (a stepped hole consisting of a front small diameter portion and a rear large diameter portion) penetrating the shaft center through a locking wall portion 22. It will be installed.

The holder 2 of this embodiment differs from the restriction wall portion 7 formed at the bottom of the through hole 23 of the holder 2 of the first embodiment in that at the rear end of the holder 2 (rear end of the mounting cylinder portion 24).
An inclined flat surface portion 71 that is inclined with respect to the axis is provided, and thereby the restriction wall portion 7 of the valve chamber 6 is configured. Examples of the method of manufacturing the inclined flat surface portion 71 include a method of obliquely cutting the rear end face perpendicular to the axis of the mounting cylinder portion 24 of the holder 2 or a method of integrally molding by injection molding of synthetic resin. Both are easy manufacturing methods.

5 and 6 show a third embodiment of the present invention. A holder 2 made of synthetic resin (for example, polyacetal, polypropylene, polyethylene, ABS resin, etc.) for holding the ball-point pen tip 1 at the tip is provided at the tip opening of the same straight ink containing tube 41 as in the second embodiment. It is fixed. The ink containing tube 41 is filled with the same ink and backflow preventive as in the first embodiment.

Unlike the first and second embodiments, the ball-point pen tip 1 has a ball receiving seat 13 and a ball holding space 1
5 and the ink supply path (through hole 51) are obtained by cutting and forming a metal material. Then, the entire rear end portion of the ball-point pen tip 1 is cut and removed obliquely with respect to the axis to form an inclined flat surface portion 71. Due to the inclined flat portion 71, the rear end portion of the mounting cylinder portion 24 of the holder 2 is pointed and can be smoothly inserted when press-fitted into the chip mounting hole 21 of the holder 2, and the rear end portion of the mounting cylinder portion 24 can be inserted. It is not necessary to provide a tapered chamfer or a curved surface on the outer circumference of the part.

The holder 2 has a chip mounting hole 2 at the front.
1, and a conical concave valve seat 8 is integrally formed on the rear inner wall thereof. Further, the holder 2 is integrally formed with a mounting cylinder portion 24 at a rear portion and a collar portion 26 at a front portion thereof,
The mounting cylinder portion 24 is press-fitted into the tip opening portion of the ink containing tube 41, and the collar portion 26 is in contact with the leading edge of the ink containing tube 41.

The valve chamber 6 is provided in the tip mounting hole 21. A regulating wall portion 7 formed by the rear end surface of the ballpoint pen tip 1 and a valve seat 8 integrally formed on the inner wall of the holder 2.
A metallic spherical valve body 9 is housed between and in such a manner that it can be moved back and forth.

FIG. 7 and FIG. 8 show a fourth embodiment (modification of the first embodiment) of the present invention. In the regulation wall portion 7, two inclined flat surface portions 71 are formed in a convex shape (or Λ shape) so that their ridge lines are located in the through holes 51 of the axial center. As a result, the valve body 9 when it comes into contact with the restriction wall portion 7 can be moved outward from the axial center, and a large ink circulation gap can be secured. The other structure is the same as that of the first embodiment.

FIG. 9 and FIG. 10 show a fifth embodiment (modification of the second embodiment) of the present invention. At the rear end of holder 2,
A right-angled flat surface portion 72 perpendicular to the axis is left in the center, and two chamfered inclined flat surface portions 71 are provided on both sides of the flat surface portion 72 so as to open into the through hole 51, and the regulation wall portion 7 is formed. . When the valve body 9 comes into contact with the regulation wall portion 7, the inclined flat surface portion 71 forms a sufficient ink flow gap for writing. The other structure is the same as that of the second embodiment.

[0036]

As described above, according to the present invention, the structure is simple and the manufacturing is easy because the regulating wall portion has the function of smoothly flowing ink during writing and the function of sufficiently abutting the valve body. A ballpoint pen having a check valve mechanism can be obtained.

Since the valve chamber is provided in the holder and one of the restricting wall portion or the valve seat is provided integrally with the holder and the other one is provided separately from the holder, the valve chamber and the restricting wall portion are provided. ,
Also, the valve seat can be easily configured with two members.

Further, since the rear end portion of the member having the inclined flat surface portion at the rear end portion is sharpened by the inclined flat surface portion, it is not necessary to provide the rear end portion with a tapered chamfer or a curved surface R and the like. Can be easily inserted into the room, facilitating assembly work.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part of a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a longitudinal sectional view of a main part of a second embodiment of the present invention.

4 is a cross-sectional view taken along the line BB of FIG.

FIG. 5 is a vertical cross-sectional view of a main part of a third embodiment of the present invention.

6 is a cross-sectional view taken along the line CC of FIG.

FIG. 7 is a vertical cross-sectional view of a main part of a fourth embodiment of the present invention.

8 is a cross-sectional view taken along the line DD of FIG.

FIG. 9 is a longitudinal sectional view of an essential part of a fifth embodiment of the present invention.

10 is a cross-sectional view taken along the line EE of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ballpoint pen tip 11 Pipe 12 Tip edge part 13 Ball receiving seat 14 Ball 15 Ball holding space 16 Support tube 2 Holder 21 Tip mounting hole 22 Locking wall part 23 Distribution hole 24 Mounting tube part 25 Step part 26 Collar part 3 Pen tip 4 Ink Storage Section 41 Ink Storage Tube 41a Small Diameter Section 41b Medium Diameter Section 5 Ink Flow Path 51 Through Hole 6 Valve Chamber 7 Control Wall Section 71 Inclined Flat Section 72 Right Angle Flat Section 8 Valve Seat 81 Annular Body 81a Valve Hole 9 Valve Body

Claims (5)

[Claims] 1. A valve chamber (6) in which a valve body (9) for preventing backflow is housed so as to be movable back and forth, and an ink flow passage (between the pen nib (3) and the ink container (4) ( 5), further,
A regulation wall portion (7) is provided on the front side of the valve chamber (6) with which the valve body (9) can come into contact when moved forward, and on the other hand, the regulation wall portion (7) is moved rearward of the valve chamber (6) rearward. When the valve body (9)
A ball-point pen provided with a valve seat (8) that can be in close contact with,
A ball-point pen characterized in that an inclined flat surface portion (71) which is inclined with respect to an axis is provided on the restriction wall portion (7). 2. The ball-point pen according to claim 1, wherein a through hole (51) for connecting the pen tip (3) side and the inside of the valve chamber (6) is opened in the inclined flat surface portion (71). 3. The ballpoint pen according to claim 1, wherein the valve body (9) is spherical. 4. A holder (2) made of synthetic resin, which holds a ball-point pen tip (1) on the front part and has a valve chamber (6) inside, is fixed to the tip opening of the ink containing tube (41). 2. The control wall portion (7) or the valve seat (8) is integrally provided with the inner wall of the holder (2), and the other one is provided separately from the inner wall of the holder (2). 2. The ballpoint pen according to 2 or 3. 5. A member having an inclined flat surface portion (71) at a rear end thereof is press-fitted into a front portion of the valve chamber (6).
The described ballpoint pen.